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Re: RFC: New approach to --with-cpu
On Wed, Jul 31, 2002 at 02:35:21PM +0100, Richard Sandiford wrote:
> Daniel Jacobowitz <drow@mvista.com> writes:
> > > I suppose you could have:
> > >
> > > if (!option_present (*argcp, *argvp, "-march=")
> > > && (!option_present (*argcp, *argvp, "-mips")
> > > || option_present (*argcp, *argvp, "-mips16")))
> > > add_option (argcp, argvp, "-march=" XSTRING (TARGET_DEFAULT_OPTION_ARCH));
> > >
> > > (since -mips16 shouldn't change the default arch) but maybe
> > > there needs to be some sort of target macro?
> >
> > That doesn't do quite the right thing, if you think about the logic.
> > It'd have to be "-mips1" or "-mips2" or "-mips3" or "-mips4" or
> > "-mips5" (?) or "-mips32" or "-mips64".
>
> Well, all -mips* options are handled by one entry in TARGET_SWITCHES, so
> -mips16 overrides a previous -mips3, silly as that might be. I guess to
> be fully correct, you need to see if the last -mips option is -mips16, in
> which case you keep the default, or something else, in which case you
> don't. (half ;-)
Wait, wait a second here. I forgot to re-ask the basic question: if
the user configures --with-cpu=<blah>, and then runs the compiler with
-mips3, what _should_ happen and what _will_ happen? The result will
be both -march= and -mips3 being specified on the command line; will
the -mips3 be ignored or have some effect? You're much more familiar
with this code than I am...
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer